The availability of safe drinking water is an important health concern. The introduction of water chlorination as a standard water treatment has resulted in a significant decrease in the number of waterborne diseases. However disinfection byproducts (DBPs) are formed by the reactions between chlorine and the natural organic matter (NOM), bromide, and iodide dissolved in water. Long-term exposure to DBPs increases the risk of cancer and other adverse health effect. As a consequence, the U.S. Environmental Protection Agency (EPA) has implemented stringent limits for some DBPs in drinking water. The use of alternative disinfectants is gaining popularity since they lower the levels of regulated DBPs. However, they form high levels of new and/or unregulated DBPs, some of which are more cytotoxic and genotoxic than regulated DBPs. Similar situation occurs when drinking water utilities exploit the use of source waters impaired by wastewater effluents beyond pristine water supplies to accommodate drinking water needs of population growth. These changes to drinking water disinfection are creating a host of emerging, highly toxic DBPs, raising concern because EPA's regulated DBPs are not necessarily the most toxic or common DBPs. And water plant approaches to reduce NOM in source water prior to disinfection are not technically sound because it requires a new water treatment plant that is costly to construct and operate. Thus, new methods to eliminate DBPs in drinking water at the point-of-use (POU) are strongly needed. During the current Phase II grant, a new photocatalytic oxidation system for POU water treatment is being developed. The aim is to provide a unique, safe, low-cost consumer device designed to effectively eliminate DBPs and microorganisms at the location where water is consumed. Our photocatalytic system has successfully treated water samples containing regulated DBPs. In addition, this POU system considerably improves drinking water quality by degrading both microorganisms and DBPs well bellow EPA levels. To address raising concern related to emerging DBPs, we request funding for this Revision Application to expand the scope of the specific aims, research design, and methods of the current Phase II grant by carrying out studies in the destruction of toxic, unregulated, emerging DBPs using Lynntech's photocatalytic system. If our product is successful, we will contribute not only to solve a serious health threat (by rendering DBPs harmless (independent of the disinfecting agent used by the water treatment plant) and providing safe, clean drinking water), but also by helping the American economy: by acquiring Amercican technology essential to expand the goals of the current grant and by hiring, training, and supporting personnel to carry out work to accomplish the Revision Application goals. In addition, Lynntech's product will be sold to American hospitals and schools, and through normal channels of commercialization, it will be sold to American households. PUBLIC HEALTH RELEVANCE: While it is vitally important to disinfect drinking water, as thousands of people died from waterborne illnesses before disinfection practices were started in the early 1900s, it is also important to minimize the exposure to disinfection byproducts (DBPs), which are formed by the reactions between the disinfecting agent and the natural organic matter (NOM), bromide, and iodide dissolved in water. Long-term exposure to DBPs increases the risk of cancer and other adverse health effect. The goal of this Competitive Revision Application is to support the expansion of the Phase II scope (that demonstrated Lynntech's POU photocatalytic system successful destruction of regulated DBPs) by demonstrating the effective destruction of toxic, emerging, unregulated DBPs, some of which are more cytotoxic and genotoxic than EPA's regulated DBPs.